Emlid Reach RS4

Emlid Reach RS4 - Survey-Grade RTK GNSS Receiver

The Emlid Reach RS4 is Emlid’s flagship all-band RTK GNSS receiver, delivering true survey-grade centimetre accuracy even in the most challenging environments. Designed for professionals who demand reliability, speed, and precision, the RS4 combines next-generation IMU tilt compensation, full multi-constellation GNSS tracking, rugged construction, and seamless field-to-cloud workflows.

Whether you’re surveying under canopy, working on construction sites, mapping terrain, or supporting drone operations, the Reach RS4 is built to perform.

Survey-Grade Accuracy - Even Under Canopy

The Reach RS4 tracks all major satellite constellations and frequencies, including the more interference-resistant L5 and L6 bands. With 672 tracking channels and the ability to track 40+ satellites simultaneously, it maintains stable RTK fixes in environments where other receivers struggle.

This results in reliable centimetre-level accuracy, even near buildings, trees, or reflective surfaces.

Next-Generation IMU Tilt Compensation

Work faster without sacrificing accuracy.

The RS4’s advanced IMU tilt compensation allows precise measurements without keeping the pole perfectly vertical. Even at a 30° tilt, the RS4 achieves up to 18 mm precision, dramatically improving efficiency in tight or obstructed areas.

Activates with just a few movements

No frequent recalibration required

Stable and reliable throughout the survey

Perfect for kerbs, boundaries, walls, and hard-to-reach points.

Precision Quick-Release Mount

Tilt compensation is only as accurate as the connection to the pole.

The RS4’s purpose-built quick-release mount eliminates backlash and movement between the receiver and pole, ensuring maximum accuracy when tilted. It provides a secure, repeatable fit while allowing fast attachment and removal in the field.

Flexible RTK: Base, Rover & NTRIP

The Reach RS4 adapts to your workflow:

NTRIP RTK

Works with VRS or single-baseline CORS networks

Supports RTCM3 format

Can act as or connect to an NTRIP base via Emlid NTRIP Caster

Dual-Band Radios (Built-In)

UHF 450 MHz

Transmit & receive

Up to 2W output (licence may be required)

Compatible with Reach and select third-party receivers supporting TRIMTALK 450S

LoRa 915 MHz

Transmit & receive

Up to 1W output (licence-free in North America)

Optimised for Reach receivers

Built for Harsh Environments

Magnesium Alloy Body

The RS4 features a lightweight magnesium alloy chassis, commonly used in aerospace and high-end electronics. It offers exceptional durability without unnecessary weight - ideal for demanding field use.

All-Day Power

Up to 16 hours of operation on a single charge

USB-C charging

Can be powered from a power bank for extended sessions

IP68 Waterproof & Dustproof

Fully sealed against dust, rain, snow, and construction site conditions.

Extreme Temperature Rated

Operates reliably from -40°C to +65°C, making it suitable for year-round use in the UK and beyond.

Emlid Flow - Field to Cloud Software

The Reach RS4 is powered by Emlid Flow, a modern mobile and cloud ecosystem available on iOS and Android.

Easy field setup and control

Real-time RTK status monitoring

Cloud project sync and team collaboration

Seamless data export to industry-standard formats

Designed to keep projects organised, teams aligned, and workflows efficient.

Ideal For

Land surveying

Construction & civil engineering

Mapping & GIS

Drone surveying & ground control points (GCPs)

Utilities, infrastructure & environmental work